91009097 has 4 divisors (see below), whose sum is σ = 91363476. Its totient is φ = 90654720.

The previous prime is 91009081. The next prime is 91009123. The reversal of 91009097 is 79090019.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43178041 + 47831056 = 6571^2 + 6916^2 .

It is a cyclic number.

It is not a de Polignac number, because 91009097 - 2⁴ = 91009081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91003097) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176804 + ... + 177317.

It is an arithmetic number, because the mean of its divisors is an integer number (22840869).

Almost surely, 2^91009097 is an apocalyptic number.

It is an amenable number.

91009097 is a deficient number, since it is larger than the sum of its proper divisors (354379).

91009097 is a wasteful number, since it uses less digits than its factorization.

91009097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354378.

The product of its (nonzero) digits is 5103, while the sum is 35.

The square root of 91009097 is about 9539.8688146117. The cubic root of 91009097 is about 449.8091322235.

The spelling of 91009097 in words is "ninety-one million, nine thousand, ninety-seven".